Viscous cleaning compositions with improved foam collapse

ABSTRACT

An aqueous viscous composition comprises: (a) from 0.5% to 1.2% of an ingredient comprising an amine, amine oxide or a mixture thereof; (b) between 4% and 7% of an ingredient comprising a secondary alkyl sulfate, secondary alkyl sulfonate, primary monobranched alkyl sulfate, primary monobranched alkyl sulfonate or mixture thereof, (c) between 2% and 4% hydrotrope; and (d) between 4% and 8% citric acid. The amount of component (b) is in excess of component (a), and the composition has a pH of from 3 to 4. A 1.2%, by weight, aqueous solution of the composition has an average rate of foam collapse of from 1.00 to 1.50 cm/min.

TECHNICAL FIELD

The present invention relates to liquid compositions for cleaning hardsurfaces.

BACKGROUND

It is well known in the art that it is a desirable feature of a liquidhard surface cleaner that it should have a certain viscosity. Indeed,viscosity allows a controlled handling, more specifically dispensing, ofthe product during use, as compared to a thinner product. Also,viscosity allows a better action of the product on non-horizontalsurfaces, such as toilets, bath tubs and the like. That is becauseviscosity prevents the product from running down said surfaces, likethinner liquids would. Preferably, viscosity will be built up by aso-called self-thickening system as opposed to using a thickenercompound for that specific purpose. Indeed, thickeners, such as gums orpolymers have at least one drawback that they affect the formula cost,while providing only one benefit, which is thickening. They do notparticipate to the actual cleaning of the surface and thereforerepresent "inert" materials. Also, some thickeners are detrimental tothe physical stability of the products they are formulated in. It isknown in the art to formulate self thickened compositions where thethickening is achieved without the use of polymeric thickeners, see forinstance EP 518 401 and EP 21 581.

But there are some drawbacks associated with viscosity. And a maindrawback is that viscous products are typically difficult to rinse away,specifically because viscous products have a good cling onto surfacesand current self thickening systems lead to the formation of stablefoams. Thus viscosity and ease of rinsing are somewhat conflictingrequirements, but both are desirable in a single product for cleaninghard surfaces. It is thus an object of the present invention to providea hard surface cleaning composition which is viscous by means of a selfthickening system, and which is nevertheless easy to rinse away.

In response we have found that such a composition could be formulated byusing an amine oxide, an amine or mixtures thereof, in combination witha secondary or primary monobranched alkyl sulfate or sulfonate in amildly acidic system further comprising a hydrotrope and citric acid. Anadditional benefit derived from said compositions is that they are lowfoaming, both in the sense of the amount of foam initially generatedduring use, as well as in terms of foam stability. This benefit adds tothe ease of rinsing benefit already obtained with the "mechanistic"benefit derived from the viscosity profile of the composition.

SUMMARY OF THE INVENTION

The present invention is an aqueous viscous composition comprising anamine oxide, or an amine or mixtures thereof, a secondary, or primarymonobranched alkyl sulfate or sulfonate in excess of said amine oxide,amine or mixtures thereof, a hydrotrope, and an organic acid, saidcomposition being formulated at a pH of from 0.5 to 7.

DETAILED DESCRIPTION OF THE INVENTION

The compositions according to the present invention are aqueouscompositions. Therefore they comprise from 90% to 60% by weight of thetotal composition of water. One of the achievements of the presentinvention is that the viscosity build up described hereinafter can beachieved with such a high amount of water, i.e. a small amount ofactives.

As a second essential ingredient, the compositions herein comprise anamine oxide, or amine, or mixtures thereof. Suitable amine oxides to beused according to the present invention are according to the formulaR1R2R3NO, where R1 is a hydrocarbon chain comprising from 6 to 18 carbonatoms, and R2 and R3 are independently hydrocarbon chains comprising upto 3 carbon atoms, or mixtures thereof. Preferred amine oxides for useherein are amine oxides where R1 comprises from 8 to 14 carbon atoms,preferably are C8-C10 amine oxide or C12-C14 amine oxide and R2 and R3are both methyl. Such a C8-C10 amine oxide is commercially availableunder the trade name Barlox® 10S, from Lonza. Such a C12-C14 amine oxidesuitable to be used herein is commercially available under the nameGenanimox® LA from Hoechst. Another suitable amine oxide for use hereinwhich is commercially available is Aromox® DMMCO-W from Akzo. Suitableamines to be used according to the present invention are according tothe formula R1R2R3N, where R1 is a hydrocarbon chain comprising from 6to 18 carbon atoms, and R2 and R3 are independently hydrogen orhydrocarbon chains comprising up to 3 carbon atoms, or mixtures thereof.Preferred amines for use herein are amines where R1 comprises from 8 to12 carbon atoms and R2 and R3 are independently methyl or hydrogen.

Preferably the total amount of amine oxides, or amines, or mixturesthereof, in the compositions according to the present invention is from0.3% to 5.0% by weight of the total composition, more preferably 0.5% to1.2%.

As a third essential ingredient, the compositions herein comprise asecondary, or primary monobranched alkyl sulfate or sulfonate, ormixtures thereof. By secondary alkyl sulfate or sulfonate, it is meantherein an alkyl sulfate or sulfonate where the alkyl chain comprisesfrom 10 to 16 carbon atoms, preferably from 12 to 14, and where thisalkyl chain is not sulfated or sulfonated at either terminus. By primarymonobranched sulfate or sulfonate, it is meant herein an alkyl sulfateor sulfonate where the alkyl chain comprises from 10 to 16 carbon atoms,preferably from 12 to 14, and where this alkyl chain is branched,comprises an alkyl substituent, at least one carbon removed from thesulfate or sulfonate group, i.e. in position 2 or further on the alkylchain, numbering from the sulfate or sulfonate group. We have found thatit is essential to have a branched alkyl chain, i.e. using a linearalkyl chain does not provide the benefits according to the presentinvention, but it appears that it does not matter which branching ispresent in the alkyl chain. We have obtained good results using an alkylsulfate where the alkyl chain comprised a total of 12 carbon atoms,sodium 2-butyl octyl sulphate. Such an alkyl sulfate is commerciallyavailable from Condea under the trade name Isofol® 12 S. An example ofan alkyl sulphonate would be Hostapur® SAS available from Hoechst. Theamount of secondary, or primary monobranched alkyl sulfate or sulfonatepresent in the compositions herein depends amongst other things on theamount of amine oxide, or amine or mixtures thereof present, butsuitable amounts of secondary, or primary monobranched alkyl sulfates orsulfonates herein are generally comprised between 3% and 20% by weightof the total composition, preferably between 4% and 7%. It is essentialthat the compositions herein should comprise said secondary, or primarymonobranched alkyl sulfate or sulfonate in excess of amine oxide, amineor mixtures thereof, i.e. in the compositions herein, the amount ofalkyl sulfate or sulfonate should be greater than the amount of amineoxide, amine or mixtures thereof.

As a fourth essential ingredient, the compositions herein comprise anorganic acid, or mixtures thereof. Preferably, the organic acids for useherein will have a pK of less than 6. Suitable such organic acids areselected from the group consisting of citric acid, lactic acid, glycolicacid, succinic acid, glutaric acid and adipic acid, and mixturesthereof. A mixture of said acids suitable for use herein is commerciallyavailable from BASF under the trade name of Sokalan® DCS. A preferredacid for use herein is citric acid. Such acids have been found toprovide the desired benefit in viscosity build up as well as compositionstability. We have found that no phase separation occurred for at least30 days at 20° C., and up to 30 days at 50° C. in the case of citricacid. The amount of organic acid herein may vary depending on the amountof other ingredients herein, but suitable amounts of acids herein aregenerally comprised between 1 % and 20% by weight of the totalcomposition, preferably between 4% and 8%, particularly when citric acidis used.

The fifth essential ingredient herein is a hydrotrope. By hydrotrope, itis meant herein an agent which helps solubilizing the hydrophobicingredients in the compositions. We have found that the hydrotropeparticipates to the building of the viscosity and contributes toincrease the stability of the composition. Suitable hydrotropes for useherein include nonionic surfactants and organic solvents, and mixturesthereof. Suitable nonionics for use herein are alkoxylated alcoholsgenerally comprising from 6 to 16 carbon atoms in the 20 alkyl chain ofthe alcohol. Typical alkoxylation groups are ethoxy and propoxy groups.Such compounds are commercially available under the series Dobanol® fromShell, or Lutensol® from BASF with a wide variety of chain length andalkoxylation degrees. Preferred nonionic surfactants for use herein areaccording to the formula R(X)nH, were R is an alkyl chain having from 6to 16 carbon atoms, preferably 6 to 10, X is an alkoxy group, preferablyethoxy or a mixture of ethoxy and propoxy, n is an integer of from 4 to30 preferably 5 to 8. Suitable solvents for use herein are organicsolvents, preferably alcohols or ethers thereof, or mixtures thereof.Commonly available solvents which are suitable for use herein includenormal-butoxy propoxy propanol (n-BPP), propane diol and butyl diglycolether (BDGE). The amount of hydrotrope may vary depending on the amountof other ingredients herein, but suitable amounts of hydrotrope hereinare generally comprised between 1% and 10% by weight of the totalcomposition, preferably between 2% and 4%.

The sixth essential feature herein is the pH, which is required to be offrom 0.5 to 7. But we have observed that, as the compositions herein areformulated close to the higher end of this pH range, the lower theoverall solubility of the composition, thus the more difficult it is toincorporate hydrophobic ingredients, typically perfumes. Also, beyond pH7, we have not been able to provide the desired viscosity. At theopposite end, as the pH gets low a higher amount of the amine oxidedescribed hereinbefore is needed. A preferred pH range herein is of fromabout 2 to 6, most preferably 3 to 4.

The compositions herein can be made by mixing together all ingredientskeeping as the last one the amine oxide, or amine or mixtures thereof,or the secondary, or primary monobranched alkyl sulfate or sulfonate.Until this last ingredient is added, no or little viscosity build up isobserved. Then, upon adding the amine oxide, amine or mixtures thereof,or the secondary, or primary monobranched alkyl sulfate or sulfonate, anopaque solution is formed which thickens on the complete addition of allcomponents. This opaque solution becomes less opaque on thickening. Andin some cases transparent products have been obtained. Under an opticalmicroscope the opacity can be seen to be due to a bicontinuous phase,which on thickening, we speculate, leads to the formation of tightlypacked vesicles which provides the desired viscosity. It would appearthat there remains a non-solubilized component present. The compositionsherein eventually reach a viscosity of from 50 cps to 5000 cps at 60 RPMshear rate with spindle #2 with a Brookefield viscometer, preferablyfrom 100 cps to 300 cps.

In this system, it is believed that the amine oxide and/or amine areprotonated, due to the acidic pH, and form an ion pair with thesecondary alkyl sulfate or sulfonate in the system. This ion pairconstitutes a hydrophobic specie. We speculate that the secondary alkylsulfate, which is present in excess, in combination with thehydrotrope/hydrotropic species and the organic acid, forms anextended/network structure within the aqueous phase. This leads to thethickening of the composition to provide the desired viscosity.Additionally, the presence of the hydrophobic ion pair per se appears toconfer antifoaming properties, thus leading to a rinsing benefit.

As an optional but highly preferred ingredient, compositions herein willcomprise a perfume ingredient, usually a mixture of such ingredients.Indeed, perfume ingredients which are typically hydrophobic materialshas been found to provide a contribution to building viscosity, perhapsthrough supporting the phase structure of the product, as well asimproving the overall stability of the product. By perfume, it is meantherein constituents of a perfume which are added thereto only orprimarily for their olfactive contribution. Perfume components may benatural products such as essential oils, absolutes, resinoids, resins,concretes, etc., and synthetic perfume components such as hydrocarbons,alcohols, aldehydes, ketones, ethers, acids, acetals, ketals, nitriles,etc., including saturated and unsaturated compounds, aliphatic,carbocyclic and heterocyclic compounds. Examples of such perfumecomponents are: geraniol, geranyl acetate, linalool, linalyl acetate,tetrahydrolinalool, citronellol, citronellyl acetate, dihydromyrcenol,dihydromyrcenyl acetate, tetrahydromyrcenol, terpineol, terpinylacetate, nopol, nopyl acetate, 2-phenylethanol, 2-phenylethyl acetate,benzyl alcohol, benzyl acetate, benzyl salicylate, benzyl benzoate,styrallyl acetate, amyl salicylate, dimenthylbenzylcarbinol,trichloromethylphenycarbinyl acetate, p-tert.butylcyclohexyl acetate,isononyl acetate, vetiveryl acetate, vetiverol, alpha-n-amylcinammicaldehyde, alpha-hexyl-cinammic aldehyde,2-methyl-3-(p-tertbutylphenyl)-propanal,2-methyl-3(p-isopropylpheny)propanal, 3-(p-tertbutylphenyl)propanal,tricyclodecenyl acetate, tricyclodecenyl propionate,4-(4-hydroxy-4-methylpentyl)-3-cyclohexenecarbaldehyde,4-(4-methyl-3-pentenyl)-3cyclohexenecarbaldehyde,4-acetoxy-3-pentyl-tetrahhydropyran, methyl dihydrojasmonate,2-n-heptyl-cyclopentanone, 3-methyl-2-pentyl-cyclopentanone, n-decanal,n-dodecanal, 9-decenol-1, phenoxyethyl isobutyrate, phenylacetaldehydedimenthyl acetal, phenylacetaldehyde dietyll acetal, geranonitrile,citronellonitrile, cedryl acetate, 3-isocamphyl-cyclohexanol, cedrylether, isolongifolanone, aubepine nitrile, aubepine, heliotropine,coumarin, eugenol, vanillin, diphenyl oxide, hydroxycitronellal,ionones, methyl ionones, isomethyl ionones, irones, cis-3-hexenol andesters thereof, indane musks, tetralin musks, isochroman musks,macrocyclic ketones, macrolactone musks, ethylene brassylate, aromaticnitromusk. Compositions herein typically comprise from 0.1% to 2% byweight of the total composition of a perfume ingredient, or mixturesthereof, preferably from 0.1% to 1.0%.

The compositions herein may comprise a variety of other ingredients,including further actives as well as mere aesthetical ingredients suchas dyes and the like. In particular the rheology of the compositionsherein would be suitable for suspending particles in the composition,e.g. particles of abrasives.

EXAMPLES--EXPERIMENTAL DATA

The present invention is further illustrated by the following examplesand data. The following compositions are made by mixing the listedingredients in the listed proportions in the listed order of addition.

    __________________________________________________________________________               Formula    Ingredient 1  2  3  4  5   6  7  8  9    __________________________________________________________________________    Citric acid               5.50  5.50                        5.50                           5.50                               5.50                                  5.50                                     9.50                                        4.00    Lactic acid   5.50    Isofol 12S ® 2.00    Alkyl sulfate    2.00    (based on    Lial alcohol)    Alkyl sulfate               4.00                  4.00     4.00                               4.00                                  4.00                                     7.50                                        4.00    (based on    Isalchem 123 ®    alcohol)    Hostapur SCS ®  4.00    Ammonia    0.75                  0.20                     0.50                        0.50                           0.50                               0.40                                  1.65                                     0.80                                        0.33    (as NH.sub.4 OH)    Propane diol  1.30     1.30                               1.30                                  1.30                                     2.40    Dobanol 79-6 ®               3.00                  3.00                     3.00                        3.00      3.00                                     5.60    Lutensol AO30  ®       3.00    n-BPP                  3.00         2.50    Perfume    0.60                  0.60                     0.60                        0.60                           0.60                               0.60                                  0.60                                     1.12                                        0.50    C8-10 Dimethylamine    oxide      0.90                  1.10                     0.80                        1.10                           0.45                               4.40                                  0.30                                     1.50    C12 alkyl amine                     1.10    pH         4.0                  3.0                     3.2                        3.2                           3.2 3.2                                  6.0                                     3.2                                        3.7    Viscosity, cps               140                  300                     170                        185                           140 350                                  135                                     940                                        140    (60 rpm, spindle#2, Brookfield, 20° C.)    __________________________________________________________________________

All the above formulations are indicated as % by weight with theremaining portion being water. All of the above formulations werestable. In the examples hereinabove, Lial alcohol (from Enichem) isC12-15 alcohol, 50% branched and 50% linear. We used the sodium salt ofthe sulfate made from this material. Isalchem 123® (from Enichem), is aC12-13, which is 94% branched. The material can be described as CH₃--(CH₂)m--CH(CH₂ OSO₃ Na)--(CH₂)n--CH₃ where n+m=8-9. Isofol 12S® (Fromcondea) is Sodium 2-butyl octyl sulfate. Hostapur SAS® is C12-16 Sodiumparaffin sulfonate. Lutensol® AO 30 is a C13-15 alcohol ethoxylated withaverage 30 moles ethylene oxide per mole alcohol.

Ease of rinsing is simulated under laboratory conditions by measuringthe foam generated from a dilute solution of the product in water (1.2%by weight). The foam height generated after a sponge is soaked andsqueezed in the solution 10 times is recorded, as well as the rate offoam collapse. Compositions 1 to 8 above according to the presentinvention are compared to a commercially available, self thickenedcomposition comprising the following ingredients:

    ______________________________________    Primary C12-14 - sodium alkyl sulphate                              3.40%    Citric acid               5.50%    Ammonium hydroxide        0.30%    Dobanol ® 23-3        0.85%    (C12-13 alcohol ethoxylated with average 3 moles of    ethylene oxide/mole alcohol)    Triethanolamine           1.90%    Perfume                   0.40%    Minors and Water          Balance    ______________________________________

The results were as follows:

    ______________________________________                          Rate of foam collapse    Product:  Foam height (cm)                          (average cm/min)    ______________________________________    Ref       4.5         0.25    1         4.0         1.40    2         3.5         1.50    3         4.0         1.00    4         3.5         1.50    5         3.0         1.40    6         3.5         1.50    7         4.0         1.20    8         5.5         1.30    ______________________________________

The above results show that for each and everyone of the compositionsformulated in the above examples, there was less foam generated, and thefoam which was generated collapsed quicker, overall providing an easierrinsing.

I claim:
 1. An aqueous viscous composition comprising:(a) from 0.5% to 1.2% of an ingredient comprising an amine, amine oxide or a mixture thereof; (b) between 4% and 7% of an ingredient comprising a secondary alkyl sulfate, secondary alkyl sulfonate, primary monobranched alkyl sulfate, primary monobranched alkyl sulfonate or mixture thereof; (c) between 2% and 4% hydrotrope; and (d) between 4% and 8% citric acid;wherein the amount of component (b) is in excess of component (a), the composition has a pH of from 3 to 4 and wherein a 1.2%, by weight, aqueous solution of the composition has an average rate of foam collapse of from 1.00 to 1.50 cm/min.
 2. A composition according to claim 1, further comprising from 60% to 90%, by weight, water and wherein the composition exhibits no phase separation for at least 30 days at 20° C.
 3. A composition according to claim 2, wherein the organic acid is citric acid and further wherein the composition exhibits no phase separation for at least 30 days at 50° C.
 4. A composition according to claim 1, further comprising an abrasive.
 5. A composition according to claim 1, wherein component (a) comprises an amine oxide having the formula R⁴ R⁵ R⁶ NO wherein R⁴ is a hydrocarbon chain comprising from 6 to 18 carbon atoms, and R⁵ and R⁶ are each independently hydrogen or a hydrocarbon chain comprising up to 3 carbon atoms; and component (b) comprises a C₁₂₋₁₃ 2-alkyl sodium sulfate having the formula CH₃ --(CH₂)m--CH(CH₂ OSO₃ Na)--(CH₂)n--CH₃, wherein n+m=8-9.
 6. A composition according to claim 1, wherein the composition has a viscosity of from 50 cps to 5000 cps at 60 RPM shear rate.
 7. A composition according to claim 1, wherein the hydrotrope is selected from the group consisting of nonionic surfactants, solvents and mixtures thereof.
 8. A composition comprising, by weight;(a) from 0.3% to 5.0% of an amine having the formula R¹ R² R³ N, where R¹ is a hydrocarbon chain comprising from 6 to 18 carbon atoms, and R² and R³ are each independently hydrogen or a hydrocarbon chain comprising up to 3 carbon atoms, or mixtures thereof; (b) from 3% to 20% of a secondary alkyl sulfate, secondary alkyl sulfonate, primary monobranched alkyl sulfate, primary monobranched alkyl sulfonate or mixture thereof; (c) between 1% and 10% hydrotrope; (d) between 1% and 20% organic acid; and (e) from 60% to 90% water;wherein the amount of component (b) is in excess of component (a), and the composition has a pH of from 3 to
 4. 9. A composition according to claim 8, further comprising an amine oxide.
 10. A composition according to claim 8, wherein the organic acid is citric acid and further wherein the composition exhibits no phase separation for at least 30 days at 50° C.
 11. A composition according to claim 8, wherein component (b) comprises a C₁₂₋₁₃ 2-alkyl sodium sulfate having the formula CH₃ --(CH₂)m--CH(CH₂ OSO₃ Na)--(CH₂)n--CH₃, wherein n+m=8-9.
 12. A composition according to claim 8, wherein component (a) comprises an amine having the formula R¹ R² R³ N, wherein R¹ is a hydrocarbon chain comprising from 8 to 12 carbon atoms, and R² and R³ are each independently hydrogen or methyl.
 13. A composition comprising, by weight:(a) from 0.5% to 1.2% of an ingredient comprising:(i) amine having the formula R¹ R² R³ N, wherein R¹ is a hydrocarbon chain comprising from 6 to 18 carbon atoms, and R² and R³ are each independently hydrogen or a hydrocarbon chain comprising up to 3 carbon atoms; (ii) amine oxide having the formula R⁴ R⁵ R⁶ NO, wherein R⁴ is a hydrocarbon chain comprising from 6 to 18 carbon atoms, and R⁵ and R⁶ are each independently hydrogen or a hydrocarbon chain comprising up to 3 carbon atoms; or (iii) mixtures thereof; (b) from 3% to 20% of a secondary alkyl sulfate, secondary alkyl sulfonate, primary monobranched alkyl sulfate, primary monobranched alkyl sulfonate or mixture thereof; (c) between 1% and 10% of a hydrotrope; (d) between 1% and 20% of a organic acid; and (e) from 60% to 90% water;wherein the composition has a pH of from 3 to 4 and exhibits no phase separation for at least 30 days at 20° C.
 14. A composition according to claim 13, wherein the organic acid is citric acid and further wherein the composition exhibits no phase separation for at least 30 days at 50° C.
 15. A composition according to claim 13, wherein component (b) comprises a C₁₂₋₁₃ 2-alkyl sodium sulfate having the formula CH₃ --(CH₂)m--CH(CH₂ OSO₃ Na)--(CH₂)n--CH₃, wherein n+m=8-9.
 16. A composition according to claim 13, wherein the hydrotrope comprises a nonionic surfactant having the formula R(X)_(n) H, wherein R is an alkyl chain having from 6 to 16 carbon atoms, X is an alkoxy group and n is an integer of from 4 to
 30. 17. A composition according to claim 13, wherein component (a) comprises an amine having the formula R¹ R² R³ N, where R¹ is a hydrocarbon chain comprising from 6 to 18 carbon atoms, and R² and R³ are each independently hydrogen or a hydrocarbon chain comprising up to 3 carbon atoms.
 18. A composition according to claim 13, wherein the composition has a viscosity of from 50 cps to 5000 cps at 60 RPM shear rate, and wherein a 1.2%, by weight, aqueous solution of the composition has an average rate of foam collapse of from 1.00 to 1.50 cm/min.
 19. A composition according to claim 13, further comprising an abrasive. 